One main focus was to improve the user experience. For instance, the online
documentation was improved by adding explicit examples. Moreover, the new
polymake 3.1 can be used via jupyter's notebook frontend (thanks to Sebastian
Gutsche). Please try
polymake --script jupyter
(with jupyter pre-installed).

Answering to a popular request we also added some of our unit tests to the
distribution. This way it should be simple to check if building the system
worked out alright.